Acute Pyelonephritis
Acute pyelonephritis is an upper urinary tract infection involving the renal pelvis and parenchyma; fever, loin pain and systemic upset are the key clues, while sepsis or an obstructed infected system makes it an emergency.
Definition
Acute pyelonephritis is an acute bacterial infection of the renal pelvis and renal parenchyma, usually due to ascending infection from the bladder. It is an upper urinary tract infection and should be distinguished from lower UTI because systemic illness, renal complications and sepsis are more likely.
First principles
Upper-tract infection is more than cystitis
Pyelonephritis is infection of the kidney and collecting system, usually caused by ascending uropathogens. Dysuria and frequency may be present, but fever, rigors, loin pain or systemic illness indicate that the infection is not confined to the bladder. The kidney's vascularity creates a route to bacteraemia, so assess severity and sepsis risk early.
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